SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52f2ae3ba04d24066a779e7d06367f2b51ffa7b4537161027197913d80b027f4' 
  AND token = 'FGEf4ijSCnI8JEAp3nLqLdJcqi6jCvdcT5rb8c6LkDU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}